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| United States Patent |
5,082,992
|
|
Ambrose
, et al.
|
January 21, 1992
|
Inbred corn line PHP02
Abstract
According to the invention, there is provided an inbred corn line,
designated PHP02. This invention thus relates to the plants and seeds of
inbred corn line PHP02 and to methods for producing a corn plant produced
by crossing the inbred line PHP02 with itself or with another corn plant.
This invention further relates to hybrid corn seeds and plants produced by
crossing the inbred line PHP02 with another corn line or plant and to
crosses with related species.
| Inventors:
|
Ambrose; William B. (Algona, IA);
Kevern; Thomas C. (Milton, WI)
|
| Assignee:
|
Pioneer Hi-Bred International, Inc. (Des Moines, IA)
|
| Appl. No.:
|
266428 |
| Filed:
|
November 1, 1988 |
| Current U.S. Class: |
800/271; 47/DIG.1; 435/412; 800/320.1 |
| Intern'l Class: |
A01H 005/00; A01H 004/00; A01H 001/00; C12N 005/04 |
| Field of Search: |
800/1,200,250,230,DIG. 56
47/58,DIG. 1
435/240.4,240.49
|
References Cited
U.S. Patent Documents
| 4812600 | Mar., 1989 | Jensen et al. | 800/1.
|
Other References
Nowacki et al. (1972) Bull. de L'Acad. Polonaise des. Science 20 (10): pp.
695-698, Abstract relied on.
Bates et al. (1974) Dept Grain Sci Kans Londres Mexico, Cimmyt. Abstract
relied on.
Sprague et al (1977), Jn/Corn & Cern Improvement, Ed. Sprague et al.,
American Soc. Agron. Madison WI. p. 316.
Galinat (1977) Jn/Corn & Corn Improvement, Ed. Sprague et al. Ameuon Soc.
Agron, Madison WI. pp 1 & 35.
Green et al. (1982), Jn. Maize for Biological Research, Ed. Sheridan, pp.
367-372, Plant Mol. Biol. Assoc. U. Press N. Dakota.
Germplasm Resources Information Heterole, (1950) PI 181989, (1960) PI
262587.
|
Primary Examiner: Locker; Howard J.
Assistant Examiner: Benzion; Gary
Attorney, Agent or Firm: Roth; Michael J.
Claims
What is claimed is:
1. Inbred corn seed designated PHP02 having ATCC accession No.
2. A corn plant produced by the seed of claim 1.
3. Tissue culture of the plant of claim 2.
4. Tissue culture according to claim 3 comprising regenerable cells of a
plant part selected from meristematic tissue, anthers, leaves, embryos,
protoplasts, and pollen.
5. A corn plant regenerated from regenerable cells of a tissue culture
according to claim 4.
6. An inbred corn plant having all the physiological and morphological
characteristics of the seed of claim 1.
7. A method to produce a novel hybrid corn seed comprising the steps of:
a) planting in pollinating proximity seeds of corn inbred lines PHP02 and
another inbred line;
b) cultivating corn plants resulting from said planting until the time the
plants bear flowers;
c) emasculating the flowers of the plants of either inbred line;
d) allowing natural cross pollinating to occur between said inbred lines;
and
e) harvesting seed produced on said emasculated plants of the inbred line.
8. An F.sub.1 hybrid corn plant and seed thereof produced by crossing an
inbred corn plant according to claim 2 with another, different corn plant.
Description
FIELD OF THE INVENTION
This invention is in the field of corn breeding, specifically relating to
an inbred corn line designated PHP02.
BACKGROUND OF THE INVENTION
The goal of plant breeding is to combine in a single variety/hybrid various
desirable traits of the parental lines. For field crops, these traits may
include resistance to diseases and insects, tolerance to heat and drought,
reducing the time to crop maturity, greater yield, and better agronomic
quality. With mechanical harvesting of many crops, uniformity of plant
characteristics such as germination and stand establishment, growth rate,
maturity, and fruit size, is important.
Field crops are bred through techniques that take advantage of the plant's
method of pollination. A plant is self-pollinated if pollen from one
flower is transferred to the same or another flower of the same plant. A
plant is cross-pollinated if the pollen comes from a flower on a different
plant.
Plants that have been self-pollinated and selected for type for many
generations become homozygous at almost all gene loci and produce a
uniform population of true breeding progeny. A cross between two
homozygous lines produce a uniform population of hybrid plants that may be
heterozygous for many gene loci. A cross of two plants each heterozygous
at a number of gene loci will produce a population of hybrid plants that
differ genetically and will not be uniform.
Corn plants (Zea mays L.) can be bred by both self-pollination and
cross-pollination techniques. Corn has male flowers, located on the
tassel, and female flowers, located on the ear, on the same plant. Natural
pollination occurs in corn when wind blows pollen from the tassels to the
silks that protrude from the tops of the incipient ears.
The development of corn hybrids requires the development of homozygous
inbred lines, the crossing of these lines, and the evaluation of the
crosses. Pedigree breeding and recurrent selection breeding methods are
used to develop inbred lines from breeding populations. Breeding programs
combine desirable traits from two or more inbred lines or various
broad-based sources into breeding pools from which new inbred lines are
developed by selfing and selection of desired phenotypes. The new inbreds
are crossed with other inbred lines and the hybrids from these crosses are
evaluated to determine which have commercial potential.
Pedigree breeding starts with the crossing of two genotypes, each of which
may have one or more desirable characteristics that is lacking in the
other or which complement the other. If the two original parents do not
provide all of the desired characteristics, other sources can be included
in the breeding population. In the pedigree method, superior plants are
selfed and selected in successive generations. In the succeeding
generations the heterozygous condition gives way to homogeneous lines as a
result of self-pollination and selection. Typically in the pedigree method
of breeding five or more generations of selfing and selection is
practiced: F.sub.1 .fwdarw.F.sub.2 ; F.sub.2 .fwdarw.F.sub.3 ; F.sub.3
.fwdarw.F.sub.4 ; F.sub.4 .fwdarw.F.sub.5, etc.
Backcrossing can be used to improve an inbred line. Backcrossing transfers
a specific desirable trait from one inbred or source to an inbred that
lacks that trait. This can be accomplished for example by first crossing a
superior inbred (A) (recurrent parent) to a donor inbred (nonrecurrent
parent), which carries the appropriate gene(s) for the trait in question.
The progeny of this cross is then mated back to the superior recurrent
parent (A) followed by selection in the resultant progeny for the desired
trait to be transferred from the non-recurrent parent. After five or more
backcross generations with selection for the desired trait, the progeny
will be heterozygous for loci controlling the characteristic being
transferred, but will be like the superior parent for most or almost all
other genes. The last backcross generation would be selfed to give pure
breeding progeny for the gene(s) being transferred.
A single cross hybrid corn variety is the cross of two inbred lines, each
of which may have one or more desirable characteristics lacked by the
other or which complement the other. The hybrid progeny of the first
generation is designated F.sub.1. In the development of hybrids only the
F.sub.1 hybrid plants are sought. The F.sub.1 hybrid is more vigorous than
its inbred parents. This hybrid vigor, or heterosis, can be manifested in
many ways, including increased vegetative growth and increased yield.
The development of a hybrid corn variety involves three steps: (1) the
selection of superior plants from various germplasm pools; (2) the selfing
of the superior plants for several generations to produce a series of
inbred lines, which although different from each other, each breed true
and are highly uniform; and (3) crossing the selected inbred lines with
unrelated inbred lines to produce the hybrid progeny (F.sub.1). During the
inbreeding process the vigor of the lines decreases. Vigor is restored
when two unrelated inbred lines are crossed to produce the hybrid progeny
(F.sub.1). An important consequence of the homozygosity and homogeneity of
the inbred lines is that the hybrid between any two inbreds will always be
the same. Once the inbreds that give the best hybrid have been identified,
the hybrid seed can be reproduced indefinitely as long as the homogeneity
of the inbred parents is maintained.
A single cross hybrid is produced when two inbred lines are crossed to
produce the F.sub.1 progeny. A double cross hybrid is produced from four
inbred lines crossed in pairs (A.times.B and C.times.D) and then the two
F.sub.1 hybrids are crossed again (A.times.B).times.(C.times.D). Much of
the hybrid vigor exhibited by F.sub.1 hybrids is lost in the next
generation (F.sub.2). Consequently, seed from hybrid varieties is not used
for planting stock.
Corn is an important and valuable field crop. Thus, a continuing goal of
plant breeders is to develop stable, high-yielding corn hybrids that are
agronomically sound. The reasons for this goal are obvious: to maximize
the amount of grain produced on the land used and to supply food for both
animals and humans. To accomplish this goal, the corn breeder must select
and develop corn plants that have the traits that result in superior
inbred parental lines for producing hybrids.
SUMMARY OF THE INVENTION
According to the invention, there is provided a novel inbred corn line,
designated PHP02. This invention thus relates to the seeds of inbred corn
line PHP02, to the plants of inbred corn line PHP02, and to methods for
producing a corn plant produced by crossing the inbred line PHP02 with
itself or another corn line. This invention further relates to hybrid corn
seeds and plants produced by crossing the inbred line PHP02 with another
corn line or a related species.
DEFINITIONS
In the description and examples that follow, a number of terms are used
herein. In order to provide a clear and consistent understanding of the
specification and claims, including the scope to be given such terms, the
following definitions are provided:
Predicted RM. This trait, predicted relative maturity (RM), for a hybrid is
based on the harvest moisture of the grain. The relative maturity rating
is based on a known set of checks and utilizes standard linear regression
analyses and is referred to as the Minnesota Relative Maturity Rating
System.
MN RM. This represents the Minnesota Relative Maturity Rating (MN RM) for
the hybrid and is based on the harvest moisture of the grain relative to a
standard set of checks of previously determined MN RM rating. Regression
analysis is used to compute this rating.
Selection Index. The selection index gives a single measure of the hybrid's
worth based on information for up to five traits. A corn breeder may
utilize his or her own set of traits for the selection index. One of the
traits that is almost always included is yield. The selection index data
presented in the tables in the specification represent the mean value
averaged across testing stations.
Yield (Bushels/Acre). The yield in bushels/acre is the actual yield of the
grain at harvest adjusted to 15.5% moisture.
Percent Yield. The percent yield is the yield obtained for the hybrid in
terms of percent of the mean for the experiments in which it was grown.
Moisture. The moisture is the actual percentage moisture of the grain at
harvest presented in percent of the mean for the experiments in which the
hybrid was grown.
GDU Shed. The GDU is the number of growing degree units (GDU) or heat units
required for an inbred line or hybrid to reach anthesis or pollen shed
from the time of planting. Growing degree units are calculated by the
Barger Method, where the heat units for a 24-hour period are:
##EQU1##
The highest maximum used is 86.degree. F. and the lowest minimum used is
50.degree. F. For each hybrid it takes a certain number of GDUs to reach
various stages of plant development. GDUs are a way of measuring plant
maturity. The data is given in percent of the mean for the experiments in
which the hybrid was grown.
Stalk Lodging. This is the percentage of plants that do not stalk lodge,
i.e., stalk breakage, as measured by either natural lodging or pushing the
stalks and determining the percentage of plants that break off below the
ear. This is a relative rating of a hybrid to other hybrids for
standability. The data are given as the percentage of the mean for the
experiments in which the hybrid was grown.
Root Lodging. The root lodging is the percentage of plants that do not root
lodge; i.e., those that lean from the vertical axis at an approximately
30.degree. angle or greater would be counted as root lodged. The data is
given in percentage of mean of the experiments in which the hybrid was
grown.
Barren Plants. This is the number of the plants per plot that were not
barren (lack ears). The data is converted to percent of the mean for the
experiments in which the hybrid was grown.
Stay Green. Stay green is the measure of plant health near the time of
black layer formation (physiological maturity). A high score indicates
better late-season plant health. The data is given in percentage of means
of the experiments in which the hybrid was grown.
Test Weight. This is the measure of the weight of the grain in pounds for a
given volume (bushel) adjusted for percent moisture. The data is given in
percentage of mean of the experiments in which the hybrid was grown.
Cob Score. The cob score is a rating of how well the grain is shelled off
the cob and how badly the cob is broken up going through the combine. This
is given as a 1 to 9 score with 9 being good. A high score indicates that
the grain shells off of the cob well, and the cob does not break. The data
is given in percentage of means of the experiments in which the hybrid was
grown.
Grain Quality. This is a 1 to 9 rating for the general quality of the
shelled grain as it is harvested based on the color of the harvested
grain, any mold on the grain, and any cracked grain. High scores indicate
good grain quality. The data is given in percentage of mean of the
experiments in which the hybrid was grown.
Seedling Vigor. This is the visual rating (1 to 9) of the amount of
vegetative growth after emergence at the seedling stage (approximately
five leaves). A higher score indicates better vigor. The data is given in
percentage of mean of the experiments in which the hybrid was grown.
Early Stand Count. This is a measure of the stand establishment in the
spring and represents the number of plants that emerge on a per-plot basis
for the hybrid. The data is given in percentage of mean of the experiments
in which the hybrid was grown.
Plant Height. This is a measure of the height of the hybrid from the ground
to the tip of the tassel and is measured in inches. The data is given in
percentage of mean of the experiments in which the hybrid was grown.
Ear Height. The ear height is a measure from the ground to the top
developed ear node attachment and is measured in inches. The data is given
in percentage of means of the experiments in which the hybrid was grown.
Dropped Ears. This is a measure of the number of dropped ears per plot and
represents the number of plants that did not drop ears prior to harvest.
The data is given in percentage of mean of the experiments in which the
hybrid was grown.
Brittle Stalks. This is a measure of the stalk breakage near the time of
pollination of the hybrids, and is an indication of whether a hybrid would
snap or break at the time of flowering under severe winds. Data are
presented as percentage of plants that did not snap. The data is given in
percentage of means of the experiments in which the hybrid was grown.
DETAILED DESCRIPTION OF THE INVENTION
Inbred corn line PHP02 is a yellow dent corn inbred that gives superior
characteristics in hybrid combination and is an excellent parental line in
crosses for producing first generation F1 corn hybrids. PHP02 was
developed from the single cross PHG44/PHG29 by selfing and using the
ear-row pedigree method of breeding. A complete description of the
development PHP02 is given in Table No. 2. Both parents, PHG44 and PHG29
(PVP Certificate 8600047) are proprietary inbred lines of Pioneer Hi-Bred
International, Incorporated. The initial cross between PHG44 and PHG29 was
made at Johnston, Iowa and the F1 single cross was selfed at Homestead,
Fla. The F2 population was grown at Algona, Iowa and 7 ears were saved out
of the population. The F3 progenies were grown at Janesville, Wis. and
selfing and selection were practiced to develop PHP02. Testcrosses were
made to inbred testers and evaluated by the Janesville Research Station.
Based on the performance of the line per se and in testcrosses PHP02 was
then evaluated in hybrid combination and as a line per se extensively by
Pioneer Research Station across the northern Corn Belt.
The inbred is adapted over a wide area of the northern Corn Belt and can be
used advantageously in hybrids from approximately 95-114 RM based on the
Minnesota Relative Maturity Rating System for harvest moisture of the
grain. PHP02 is an outstanding female and over 162 replications of
research testing has averaged 90 bushels per acre or 126 percent of the
experimental mean. Cold test is very adequate as a female as it has
averaged 90 percent (103 percent of experimental mean) over 26 reps of
data. Kernal size out is also very good for PHP02 and it has approximately
41 percent of the kernals falling in the medium flat category. Although
PHP02's primary use would be as a female, it is also an acceptable male
with a little below average pollen shed ability. Over 12 reps of date, it
has a pollen percentage of 92 percent of the mean of 1.28 grams of pollen
per plant. Under extreme heat and drought stress, PHP02 may top fire and
have some tassel blasting (necrosis of top leaves and tassel,
respectively). It does shed for a fairly short duration and should be
planted at higher densities to ensure adequate pollen in the production of
hybrid seed corn if it is used as a male.
The inbred has shown uniformity and stability within the limits of
environmental influence for all traits as described in the Variety
Description Information. However, the line did show segregation for yellow
and purple anther color with the first foundation increase. Additional
ear-to-row selection for yellow anther type has fixed the inbred for
yellow anther color. PHP02 has been self-pollinated and ear-rowed a
sufficient number of generations with careful attention to uniformity to
plant type to ensure homozygousity and phenotypic stability. The line has
been increased both by hand and sibbed in isolated fields with continued
observation for uniformity. Besides the initial segregation for anther
color, no variant traits have been observed or are expected with PHP02.
Inbred corn line PHP02, being substantially homozygous, can be reproduced
by planting seeds of the line, growing the resulting corn plants under
self-pollinating or sibpollinating conditions with adequate isolation, and
harvesting the resulting seed, using techniques familiar to the
agricultural arts.
The data given in the Variety Description Information (Table 1) was
collected primarily at Johnston, Iowa.
TABLE 1
______________________________________
PHP02
VARIETY DESCRIPTION INFORMATION
Type: Dent
Region Best Adapated:
Most Regions
______________________________________
A. Maturity: Zone 0: Averaged across maturity zones
INBRED = PHP02
Heat Unit Shed: 1340
Heat Unit Silk: 1360
No. Reps: 67
HEAT UNITS =
##STR1##
*If maximum is greater than 86 degress fahrenheit, then
86 is used and if minimum is less than 50, then 50 is
used. Heat units accumulated daily and can not be less
than 0.
B. Plant Characteristics:
Plant height (to tassel tip): 203 cm
Length of top ear innernode: 12 cm
Number of ears per stalk: Slight two-earred tendency
Ear height (to base of top ear): 81 cm
Number of tillers: None
Cytoplasm type: Normal
C. Leaf:
Color: Medium Green (WF9)
Angle from Stalk: 30-60.degree.
Marginal Waves: Few (WF9)
Number of Leaves (mature plants): 18
Sheath Pubescence: Light (W22)
Longitudinal Creases: Absent (OH51)
Length (Ear node leaf): 86 cm
Width (widest point, ear node leaf): 94 mm
D. Tassel:
Number lateral branches: 16
Branch Angle from central spike: 30-45.degree.
Pollen Shed: Medium
Peduncle Length (top leaf to basal branches): 18 cm
Anther Color: Yellow - was segregating for purple and
yellow anther color but fixed for yellow
Glume Color: Green
E. Ear (Husked Ear Data Except When Stated Otherwise):
Length: 20 cm
Weight: 127 gm
Mid-point Diameter: 42 mm
Silk color: Salmon
Husk Extension (Harvest stage): Short (ear exposed)
Husk Leaf: Long >15 cm
Taper of Ear: Average Taper
Position of Shank (dry husks): Upright
Kernel Rows: Distinct, Straight, Number = 16
Husk Color (fresh): Light Green
Husk Color (dry): Buff
Shank Length: 10 cm
Shank (No. of internodes): 6
F. Kernel (Dried):
Size (from ear mid-point)
Length: 10 mm
Width: 7 mm
Thick: 4 mm
Shape Grade (% rounds): 20-40% based on Parent test
Pericarp Color: Colorless
Aleurone Color: Homozygous yellow
Endosperm Color: Yellow
Endosperm Type: Normal
Gm Wt/100 Seeds (unsized): 26 gm
G. Cob:
Diameter at mid-point: 25 mm
Strength: Strong
Color: Red
H. Diseases:
Northern Leaf Blight: Susceptible
Goss' Bacteria Blight: Intermediate
Southern Leaf Blight: Susceptible
Head Smut: Susceptible
Common Smut: Resistant
Stewart's Bacterial Wilt: Susceptible
Corn Lethal Necrosis: Susceptible
Northern Leaf Spot: Susceptible
Common Rust: Resistant
Eye Spot: Intermediate
Gray Leaf Spot: Susceptible
Fusarium Ear Rot: Susceptible
I. Insects:
European Corn Borer: Susceptible
J. Variety Most Closely Resembling:
Character Inbred
Maturity PHG29
Plant Type PHG29
Ear Type PHG29
Kernel Type PHG29
Usage PHG29
______________________________________
Inbred corn line PHP02 most closely resembles PHG29 in characteristics of
maturity, plant type, ear type, kernal type, and usage.
TABLE 2
______________________________________
BREEDING HISTORY FOR PHP02
Season/ Ears
Year Level Pedigree Grown Saved
______________________________________
Sum/1979 PHG44-PHG29 (cross was made)
Bulk
Win/1979
F1 PHG44/PHG29 Bulk
Sum/1980
F2 PHG44/PHG29)X 7
Sum/1981
F3 PHG44/PHG29)X1 2
Sum/1982
F4 PHG44/PHG29)X12 1
Sum/1983
F5 PHG44/PHG29)X121 3
Sum/1984
F6 PHG44/PHG29}X1211 10
Sum/1985
F7 PHP02-1 10
Sum/1986
F8 PHP02-1-9 10
Win/1986
F9 PHP02-1-9-(1-10) Bulk
Sum/1987
F10 PHP02-1-9-(1-10)-X
Sum/1987
F9 PHP02-1-9-(1-10)
______________________________________
Electrophoresis Results
Isozyme Genotypes for PHP02
Isozyme data was generated for inbred corn line PHP02 according to the
procedure described in Goodman, M. M. and Stuber, C. M., "Genetic
identification of lines and crosses using isoenzyme electrophoresis,"
Proceeding of the Thirty-Fifth Annual Corn and Sorghum Industry Research
Conference, Chicago, Ill. (1980).
Electrophoresis results comparing PHP02 to its parents, PHG44 and PHG29 are
given in Table No. 3. These results provide additional support to the
pedigree for PHP02.
TABLE 3
______________________________________
Electrophoresis results for PHP02 and its parents PHG44
and PHG29.
Alleles Present
Locus PHP02 PHG44 PHG29
______________________________________
Acp1 2 2 2
Adh1 4 4 4
Cat3 9 9 9
Dia1 8 8 8
Glu1 6 6 6
Got1 4 4 4
Got2 4 4 4
Got3 4 4 4
Idh1 4 4 4
Idh2 6 6 6
Mdh1 6 6 6
Mdh2 3.5 3.5* 3.5
Mdh3 16 16 16
Mdh4 12 12 12
Mdh5 12 12 12
Mmm -- -- --
Pgm1 9 9 9
Pgm2 4 4 4
Pgd1 3.8 3.8 3.8
Pgd2 5 5 5
Phi1 4 4 4
NO. PLANTS 10 10 10
______________________________________
*PHG44 had slower migration at Mdh2 locus than 3.5 control genotype.
INDUSTRIAL APPLICABILITY
This invention also is directed to methods for producing a corn plant by
crossing a first parent corn plant with a second parent corn plant wherein
the first or second parent corn plant is an inbred corn plant from the
line PHP02. Further, both first and second parent corn plants may be from
the inbred corn line PHP02. Thus, any methods using the inbred corn line
PHP02 are part of this invention: selfing, backcrosses, hybrid production,
crosses to populations, etc. Any plants produced using inbred corn line
PHP02 as a parent are within the scope of this invention. Advantageously,
the inbred corn line is used in crosses with other corn inbreds to produce
first generation (F.sub.1) corn hybrid seeds and plants with superior
characteristics.
As used herein, the terms "plant and plant parts" include plant cells,
plant protoplasts, plant cell tissue culture from which corn plants can be
regenerated, plant calli, plant clumps, and plant cells that are intact in
plants or parts of plants, such as embryos, pollen, flowers, kernels,
ears, cobs, leaves, husks, stalks, roots, root tips, anthers, silk and the
like.
Tissue culture of corn is described in European Patent Application,
publication 160,390, incorporated herein by reference. Corn tissue culture
procedures are also described in Green and Rhodes, "Plant Regeneration in
Tissue Culture of Maize," Maize for Biological Research (Plant Molecular
Biology Association, Charlottsville, Va. 1982, at 367-372. Thus, another
aspect of this invention is to provide for cells which upon growth and
differentiation produce the inbred line PHP02.
The utility of inbred line PHP02 also extends to crosses with other
species. Commonly, suitable species will be of the family Graminaceae, and
especially of the genera Zea, Tripsacum, Coix, Schlerachne, Polytoca,
Chinonachne, and Trilobachne, of the tribe Maydeae. Of these, Zea and
Tripsacum, are most preferred. Potentially suitable for crosses with PHP02
may be the various varieties of grain sorghum, Sorghum bicolor (L.)
Moench.
Corn is used as human food, livestock feed, and as raw material in
industry. The food uses of corn, in addition to human consumption of corn
kernels, include both products of dry- and wet-milling industries. The
principal products of corn dry milling are grits, meal and flour. The corn
wet-milling industry can provide corn starch, corn syrups, and dextrose
for food use. Corn oil is recovered from corn germ, which is a by-product
of both dry- and wet-milling industries.
Corn, including both grain and non-grain portions of the plant, is also
used extensively as livestock feed, primarily for beef cattle, dairy
cattle, hogs, and poultry.
Industrial uses of corn are mainly from corn starch from the wet-milling
industry and corn flour from the dry-milling industry. The industrial
applications of corn starch and flour are based on functional properties,
such as viscosity, film formation, adhesive properties, and ability to
suspend particles. The corn starch and flour have application in the paper
and textile industries. Other industrial uses include applications in
adhesives, building materials, foundry binders, laundry starches,
explosives, oil-well muds, and other mining applications.
Plant parts other than the grain of corn are also used in industry. Stalks
and husks are made into paper and wallboard and cobs are used for fuel and
to make charcoal.
The seed of inbred corn line PHP02, the plant produced from the inbred
seed, the hybrid corn plant produced from the crossing of the inbred,
hybrid seed, and various parts of the hybrid corn plant can be utilized
for human food, livestock feed, and as a raw material in industry.
EXAMPLE
Hybrid Performance of PHP02
In the examples that follow, the key traits and characteristics of inbred
corn line PHP02 are given for some of its hybrid combinations.
The data in Table No. 4 gives a comparison of PHP02 to PHG29 crossed to the
same tester lines and the hybrids evaluated in the same experiments at the
same locations. Both inbreds were crossed to the same seven lines and
evaluated in the Eastern, Northern, Central, and Western Regions and the
data presented is the overall summary and has 279 replications of data
averaged over testers and locations for yield. PHP02 is similar
genetically to PHG29 but does show some significant advantages. Its
hybrids tend to have a little higher yield, are earlier to flower, and are
a little better agronomically for stalk lodging resistance and staygreen
characteristics. PHP02 hybrids do tend to have lower test weight and a
little poorer grain quality than PHG29 crosses. Other attributes tend to
be very similar. Drought tolerance of PHP02 hybrids have tended to be a
little poorer than PHG29 crosses based on research testing. PHP02 crosses
can be susceptible to ear molds and its use in areas of extreme ear mold
pressure should be limited. However, the overall performance of the line
in hybrid combination as well as the outstanding female parental and
acceptable male parental characteristics make PHP02 a very important
inbred for producing commercial single cross hybrids.
TABLE 4
__________________________________________________________________________
Average inbred by tester performance comparing PHP02 to PHG29 crossed
to the same inbred testers and grown in the same experiments. All
values are expressed as percent of the experiment mean except Predicted
RM, Selection Index, and Yield (Bu./Ac.).
__________________________________________________________________________
PREDICTED
SELECTION
YIELD PERCENT GDU STALK
HYBRID RM INDEX (BU./AC.)
YIELD MOISTURE
SHED
LODGING
__________________________________________________________________________
No. of Reps 281 279 279 279 281 60 269
PHG29 Crosses
108 100 144 101 101 100 98
PHP02 Crosses
108 104 147 103 101 98 103
Difference
0 4 3 2 0 2 5
__________________________________________________________________________
EARLY
ROOT BARREN STAY TEST COB GRAIN SEEDLING
STAND
HYBRID LODGING
PLANTS GREEN
WEIGHT
SCORE
QUALITY
VIGOR COUNT
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No. of Reps 96 27 171 281 30 180 107 188
PHG29 Crosses
103 100 92 100 93 100 102 102
PHP02 Crosses
100 100 101 98 87 95 108 102
Difference
3 0 9 2 6 5 6 0
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HYBRID PLANT HEIGHT
EAR HEIGHT
DROPPED EARS
BRITTLE
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STALKS
No. of Reps 145 145 247 44
PHG29 Crosses
100 99 100 100
PHP02 Crosses
101 98 99 99
Difference
1 1 1 1
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Deposits
Applicants have made available to the public without restriction a deposit
of at least 2500 seeds of inbred PHP02 with the American Type Culture
Collection (ATCC), Rockville, Md. 20852 USA, ATCC Deposit No. 75077. The
seeds deposited with the ATCC are taken from the same deposit maintained
by Pioneer Hi-Bred International Inc., 700 Capital Square, 400 Locust
Street, Des Moines, Iowa 50309 since prior to the filing date of this
application. The deposit will be maintained in the ATCC depository, which
is a public depository, for a period of 30 years, or 5 years after the
most recent request, or for the effective life of the patent, whichever is
longer, and will be replaced if it becomes nonviable during that period.
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